J. S. BACH Jonathan Berkahn - Victoria University - Victoria ...

When tonic and dominant are brought into close proximity thus, the possibility
of dramatic opposition between the two is at once undermined; for between them they
effectively form a single composite tonal area. The Zauberflöte overture shows how
this process can be ‘quarantined’ from the rest of the movement. Its fugal exposition
is free to alternate in this way between tonic and dominant, but once the drive to the
dominant begins in earnest—around b.35, say—there is no going back and its
dominant is given far greater prominence (such as its eleven bar prolongation between
bb.38 and 48) than it could ever have in a fugue.
The tonal course of the rest of a fugue has equally little in common with sonata
principles. Rather than prioritising this I-V axis as in a sonata movement, is likely to
pay a visit to some or all its diatonic relatives (ii, iii, IV, V, and vi in the major; III, iv,
v, VI, and VII in the minor). 31 There may be entries on these pitches, analogous to the
ritornelli in a contemporary concerto movement—although is no reason to expect that
cadential arrival and thematic arrival need coincide in any particularly close manner
(also, until quite late in the seventeenth century most fugues had been quite content
with entries on I and V; this did not of course mean that these were the only keys
employed in the course of the piece.) The only large scale patterning likely to be seen
is to be a slight subdominant bias as the end approaches. As Roger Bullivant points
out, fugue is not a ‘sensitive’ form, with precise requirements of balance and
symmetry: it can be extended almost indefinitely as long as long as interest is
maintained (which is exactly what Bach did when revising some of his own fugues). 32
From this point of view, then, it would seem that the combination of fugal and
sonata principles is more problematic than it would appear to be at first sight. It is, all
the same, precisely what many composers did as a matter of course. I am not speaking
here so much of the sublime fusion of Haydn and Mozart, nor the eccentric, one-of-a-
31 Cherubini’s tonal scheme, cited on pp.21-2 above, reflects this; but, typically, he turns a range of
possible destinations into a fixed itinerary.
32 Bullivant, Fugue, p.174.
30